4. Suppose that in a double auction market there are eight sellers and 6 sellers. The buyers can purchase up to 1 unit each, and the sellers can sell up to 1 unit each. The following are the costs and values used in the experiment: Costs: 7, 10, 9, 9, 6, 10, 8, 8 Values: 7, 9, 10, 7, 10, 9 You observe that three units of the good were traded. Costs and values for these units are given in the table below. Buyer's Seller's Cost Transaction Value Price Unit 1 $10 $8 $9 Unit 2 $9 $7 $8 Unit 3 $10 $6 $7 Find economic efficiency of this market data